1. Field of the Invention
The present invention relates to a registration device and, more specifically, to a device for registering the position of an orthopedic implant in a computer assisted surgical navigation system.
2. Description of the Related Art
The controlled positioning of surgical instruments and other objects is of significant importance in many surgical procedures and various methods have been developed for properly positioning an object during a surgical procedure. Such methods include the use of both mechanical guides and computer assisted navigational systems. Computer assisted navigational techniques typically involve acquiring preoperative images of the relevant anatomical structures and generating a data base which represents a three dimensional model of the anatomical structures. The relevant tools and other objects used in the surgical procedure typically have a known and fixed geometry which is also defined preoperatively. During the surgical procedure, the position of the object being used is registered with the anatomical coordinate system and a graphical display showing the relative positions of the object and anatomical structure may be computed in real time and displayed for the surgeon to assist the surgeon in properly positioning and manipulating the object with respect to the relevant anatomical structure.
In such image guided procedures, a robotic arm may be used to position and control the object, or, the surgeon may manually position the object and use the display of the relative position of the object and anatomical structure to position the object. Examples of various computer assisted navigation systems, which are known in the art, are described in U.S. Pat. Nos. 5,682,886; 5,921,992; 6,096,050; 6,348,058 B1; 6,434,507 B1; 6,450,978 B1; 6,490,467 B1; and 6,491,699 B1, wherein the disclosures of each of these patents are hereby incorporated herein by reference.